Sand blasting apparatus



June 10, 1958 D. HUNTER 2,337,874

SAND BLASTING APPARATUS Filed June 18, 1956 2 Sheets-Sheet 1 INVEN TOR.42%? fl/Waz I True/M17 June 10, 1958 E. D. HUNTER 2,837,874

' SAND BLASTING APPARATUS Filed June 1a, 1956 2 Sheets-Sheet 2 20INVENTOR.

United States Patent 2,837,874 SAND BLASTING APPARATUS Edgar D. Hunter,Baltimore, Md.

Application, June 18, 1956, Serial No. 591,967

4 Claims. (Cl. 51-8) The present invention relates to an improved sandblasting apparatus, particularly 'to a type that is normally manuallyoperated.

The primary object of the invention is to provide means for boosting thesand from a point adjacent the supply along an exhaust hose to the pointof discharge thereof.

Another object of the invention is to provide an improved nozzle in suchan apparatus'in which the air is controlled .to both the booster and theair outlet end of the nozzle by a single valvecarried within or adjacentthe nozzle.

A further object of theinvention is to provide a methd of continuouslymoving auniformmixture of air and sand through the outer end of thenozzle.

While several objects of the invention have been pointed out, otherobjects including its uses and advantages will appear more readily asthe nature of the invention is more fully described, consisting of itsnovel feature, arrangement and combination of parts as shown in theaccompanying drawings and described in the written specification. In thedrawings:

Figure l is a fragmentary view in elevation of the apparatus.

Figure 2 is a fragmentary view in elevation of the particular type ofreceiving end for the sand which may be inserted in an ordinary sandpile. V

Figure 3 is an enlarged sectional view of the improved nozzle.

Figure 4 is an enlarged sectional view of the sand receiving end of theapparatus when the apparatus is used in connection with a hopper.

Figure 5 is a sectional view of the type of sand receiving member asshown in Figure 2.

Figure 6 is a sectional view taken along lines 6-6 of Figure 5.

In referring to the drawings like numerals are used to indicate like andsimilar parts throughout the several views.

Referring in particular to Figure 1, there is provided a hopper 10supported by a suitable frame 11. Extending below the hopper 10 is anoutlet for the sand 10' and connected to the outer end ofthe portion 10'is a booster for the sand The booster is provided with an outer 'casing12 and connected to the outer end of the casing 12 is a convenientcoupling 13 which is in turn connected with a hose member 14. The hosemember 14 leads to the nozzle 15 and is connected thereto by a suitablecoupling member 16.

Within the housing 12 there is an. air jet 20. This jet is directed inthe direction the sand is to take through the hose 14 and eventually tothe nozzle. Air is supplied to the jet through the pipe 21 at a reducedpressure from that carried in the air hose 27 leading to the nozzle. Thenozzle as shown best in Figure 3 is provided with an outer curvedhousing 22. At one end of the housing there is a rubber, or plasticlined jet 23, which is attachable to the end of the housing 22 by themember "ice tending through the outer bend of the housing or casing 22which is in line with the jet 23. i This member 25 is provided with asecond smaller jet member 26 similar to the one shown at 23 whichextends within the nozzle in rear of the jet member 23. Leading to themember 25 is an air supply hose 27 Positioned within the member 25 is avalve 28 which is operated by a lever 29. Extending through the casingof the member 25 is an opening 30. This opening is connected with an airhose 31 which in turn is connected with the pipe 21 leading to thebooster jet 20 in the booster. The flexible hose lines 14, 27 and 31 areconnected by suitable bands 32 in order that they may behandled as asingle group.

It will be noted that the opening 30 leading to the booster hose 31 islocated outwardly from the valve 28, therefore when the valve 30 isclosed, air is cut ofi from both the nozzle and the booster by thissingle valve. This is' very convenient for the operator and naturallyfollows that an operator may work more efficiently with such anapparatus.

The air carried by the main air line 27 is substantially A greater thanthe air permitted to pass through the booster jet 20. This is regulatedby a suitable regulating valve 33 where these pressures may beproportioned.

When the apparatus is in use, the hose leading from the nozzle areconnected as shown in Figure 1, that is, the air line 27 is connectedwith a suitable air supply (not shown), the hose 14 is connected withthe outer end of the booster and the hose 31 is connected with the pipe21 leading to the booster jet.

When the device is being used in an ordinary pile of sand it takestheform as shown in Figure 2, that is, the member 12' is inserted intothe sand pile 35 as shown by the dotted lines at 12". In order to keepthe receiving end of this form of the apparatus in the proper position,there is provided a foot member 36 which will prevent the casing 12 fromrotating and in proper operating position.

Whichever receiving means is used, the jet operation of the apparatus issubstantially the same. Taking for example, the preferred form as shownin Figure 1, the hopper 10 is first filled with sand, and sand is fed bygravity down through the neck 10 of the hopper to the booster. Withinthe booster shell 12 there is a jet 37 which directs a blast of airtoward and along the hose at a reduced pressure by means of the pressurereduction valve 19. The air moves along the hose 14 toward the nozzle.This blast of air picks up the sand and keeps it in suspension until ithas reached the nozzle where it is mixed with the blast of air emanatingfrom the member 26 at a much greater velocity. With this increasedvelocity this mixture of sand and air pass through the outer jet member23. The booster prevents bunching of the sand at any one place as itmoves through the hose 14. lt gives a much steadier and regular mixtureof sand and air to the surfaces being blasted than has been doneherebefore.

In using the sand receiving member as shown in Figure 5 air movesthrough the jet 20 at a reduced pressure by virtue of the control valve33 and acts in the same manner on the sand as has just been describedfor Figure 1. The device may be used with a stationary installation orit may be of a portable nature. Likewise, the apparatus may be used witha hopper, or it may be used with a mound of sand located over thereceiving end of the apparatus, as shown in Figures 2 and 5.

While the invention has been described in detail it is not intended as alimitation, as the scope of the invention is best defined in theappended claims:

What is claimed is:

l. A sand blasting apparatus having a sand receiving Patented June 10,1,9558

3 element and a nozzle for dispensing the same having an air cut-offvalve carried thereby, the sand receiving element having positionedtherein an air jet directed toward its outlet, a flexible air supplyline leading directly to the said nozzle from a suitable supply source,a, flexihousing having an inlet in one portion thereof for re ceivingthe sand conveying means and an opening in another portion of the.nozzlefto. receive an outer blasting j'et', a valve in' said. airadmitting means for control-' ling the flow of air therethrough,a'second inner air jet within the hollowhou'sin'g 'connected wi th theair admittin'g' rneans and directed centrally and rearwardly of theouterjet, an opening in the air admitting mea ns on the opposite side ofthe valve from the second mentioned inner jet adapted to be connected toan airline leading to the outside of the nozzle housing.

3. A sand-blasting apparatus having a sand receiving element and anozzle for dispensing the same, a conduit connecting the sand-receivingelement with the nozzle, a pressure air supply conduit leading to thenozzle for forcing the sand therethrough, an air control valveassociated with the nozzle for opening and closing the air supplyconduit, an air sand booster adjacent the sand-receiving element forassisting the movement of the sand through the conduit connected betweenthe sand-receiving element and the nozzle, a separate air conduitleading from the nozzle to the sand air booster, the separate airconduit having one end connected to the nozzle beyond the air controlvalve and its opposite end connected with the sand air booster forsupplying air to the booster only when the air control valve is open toallow air to flow through the nozzle.

4. A sand blasing apparatus-having a sand receiving element and a nozzlefor dispensing the same, a conduit connecting the sand receiving elementand the nozzle, an air supply conduit leading to the nozzle from an airsupply under pressure, an air control valve associated with the nozzlefor opening and closing the air supply passing through the nozzle, anair sand booster positioned adjacent the sand receiving element adaptedto direct a jet of air in the direction the sand is moving through theconduit leading from the sand receiving element to the nozzle, means forreducing the air pressure entering the sand booster relative to the airpressure moving through the nozzle, an air conduit extending from apoint beyond the air valve in thenozzle to the sand booster forsupplying air to the air booster jet only Whenthe air control valve isopen to allow air to flow through the nozzle.

Anderson June 26, 1951

